Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Impact of prey supply levels on growth performance and optimization of the mass rearing of an omnivorous mirid predator.

Abstract

Despite of the efficacy of heteropteran predators in biological control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), the high costs of their production due to the use of expensive factitious prey limit their wider use. Therefore, studies on their adaptability against fluctuations of prey supply may offer valuable inputs for optimal use of prey in their rearing. Here, we present a detailed assessment of prey deprivation effects on the developmental traits of the omnivorous predator Dicyphus errans (Wolff) (Hemiptera: Miridae). The effect of eight treatments of periodical prey provision in different nymphal instars and five treatments of continuous provision of suboptimal prey amounts during nymphal development were assessed. Nymphs fed only in early instars were able to complete their development whereas prey availability in late instars was linked to high adult weight gain. Female nymphs that showed both a very short developmental time and a very intense food consumption, at the highest prey availability levels, gained the most weight among all the treatments tested. Interestingly, nymphs fed with half of their saturation level developed similarly to those that had access to a full saturation level. The results are discussed with respect to the adaptation strategies exhibited by this predatory bug, with emphasis on implications for its mass rearing and use in biological control. The outcomes may be usefully applied in the selection and rearing of the best new candidates against T. absoluta.